


celestial sphere

by erzi



Category: Dr. STONE (Manga)
Genre: M/M, Manga Spoilers
Language: English
Status: Completed
Published: 2020-08-02
Updated: 2020-08-02
Packaged: 2021-03-05 20:35:07
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,700
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25671424
Author URL: https://archiveofourown.org/users/erzi/pseuds/erzi
Summary: And Gen reflects that to call the sky and sea black is incorrect. There is nothing in black, an absence of color. It's dark out, yes, but there are subtleties in it that a simple 'black' does not allude to. In it, there is purple, like the center of a primeval nebula far above, where they cannot see; there is blue, like what lurks in the bottom of the ocean, which too remains unknown to them. And there is white—not painted on for canvas, but speckled as the stars and the moon, full tonight.The opportunity to remark on how pretty it is is absurdly ripe in Gen's hands, but even someone like Senku would remember its old implication. And the time forthatparticular reveal isn't right.
Relationships: Asagiri Gen/Ishigami Senkuu
Comments: 22
Kudos: 77





	celestial sphere

Senku hasn't come above deck in hours. Not that it's unusual for him to toil away in his lab, but it's one thing to be on land and stay there, and another to be on the sea—among the first people in thousands of years to sail this once-prosperous route—and not come up. Especially at night, with the sea and the sky black mirrors of each other, moon and stars repeated twice so purely it doesn't seem real.

Gen takes in the sight, a fortune in the midst of a society regressed, and beautiful as it is, he's alone, and Senku could use a break. Aligned interests, in truth. The truth beneath _that_ : if everyone but Senku was on deck, it couldn't be counted full.

In the kitchen, Gen boils water and steeps tea, a ritual unchanging even in this world, and carefully brings a cup down to where Senku is.

"Senku-chan, Senku-chan," he says, peeking his head through the door, finding him watching what looks like seaweed boiling in a glass flask. Senku turns at his voice, and he steps in. "I brought you tea. Whatcha doing, cooped up here like a literal lab rat?"

"Trying to make agar, but I can't get the pH right for the acidic washing." He walks to Gen, grabs the cup, sips. Some of the tension on his shoulders melts away. "Thanks."

"Right, yes, I'll pretend I know what you mean," Gen says, and dons a smile that he'd never have used for television: this is something private. "You need a break, Senku-chan, before you get all stooped from hunkering down here!"

"I can't. Agar from seaweed is used to make agar plates for growing bacteria—if it's the right genus of seaweed. But if it's not, we can make this into jelly candy. That is," he says, scratching the side of his head, mouth downturned, "if I can get this to _work_."

"Well, you've been here for hours and hours. Let's get you some fresh air, hmm? A strike of inspiration could hit you up there! Or else rest. It's no good to overwork yourself." A remnant of the old world settles itself in Gen's mind. He calculates its worth in the instant it forms, deems it— well, worthwhile, and speaks. "Our ship is the Perseus, and there's a constellation named Perseus, right? If you go out to see it, it's like everything is coming together!"

That gets a smirk out of Senku. "I'm not five years old, mentalist," he says. "You don't need to pull that crap to get me out of here." He downs all of his tea in one go and sets the cup on an empty spot on his work table, wiping his mouth with the back of his hand. "Let's go up."

Gen had wanted him to enjoy the tea while they stargazed, but all two-hundred-odd of Senku's bones have nothing of sentiment in them. He sighs, unsurprised, fond, and leads the way.

And Gen reflects that to call the sky and sea black is incorrect. There is nothing in black, an absence of color. It's dark out, yes, but there are subtleties in it that a simple 'black' does not allude to. In it, there is purple, like the center of a primeval nebula far above, where they cannot see; there is blue, like what lurks in the bottom of the ocean, which too remains unknown to them. And there is white—not painted on for canvas, but speckled as the stars and the moon, full tonight.

The opportunity to remark on how pretty it is is absurdly ripe in Gen's hands, but even someone like Senku would remember its old implication. And the time for _that_ particular reveal isn't right.

"I never saw the sky like this back in Japan," Gen idly says. "Not that I think the petrification was a good thing, but since it happened, and there's no avoiding what has happened, I think I can at least appreciate the sky."

"It _is_ pretty exciting," Senku says, a gleam in his eye, what only science can do to him. "The Earth's axis is tilted an additional few degrees, so our view of stars is different in that way. Not to mention the millennia that have passed changed how we see constellations! The ancient Greeks saw different stars than we did in the twenty-first century, and now _we're_ seeing different things than ourselves three thousand years ago."

 _Not quite what I meant_ , Gen thinks. He smiles. Genuine, and small, small enough to be missed even if Senku was looking—and he isn't; he's captivated by the stars. But it's alright. It's probably better he doesn't see. Gen can spin lies a thousand different ways and feel little for it, but a lie for why he smiles like that would prick his fingers with each syllable spoken.

"Do you not recognize any constellations, then? Is Perseus gone?" he asks.

"No, I recognize them. I just have to consider how stars' paths would have changed through time. Though in the span of things, three thousand years is nothing to a star. They're pretty much the same. The famous Big Dipper's still up there, looking only a little worse for the wear. Still pointing to the not-really-North-Star-anymore."

It's all so obvious to Senku, but what Gen sees is a bright smattering of stars, shapeless and nameless unless he gives them purpose himself. The sky itself is different than it was before everything, but he wouldn't have known unless Senku had said so. He squints, trying to find anything that resembles what he remembers the Big Dipper being like.

Then he gets a better idea.

" _There's_ the Big Dipper!" he says, pointing at random.

"Not even close, Gen," Senku says, amused, but never condescending, as he places his hand, callused from his scientific labors, over Gen's—just as hardened from his own manual work—and moves it, or them, really, somewhere left. "There. Not very ladle-like anymore, but close enough." With Gen's finger he traces its path, anciently imagined shape drawn piece by piece in Gen's mind. "Good ol' Alkaid, Mizar, Alioth, Megrez, Phecda, Merak, Dubhe. And, if we extend an imaginary line from those two—" Senku trails Gen's finger down a patch of empty sky, steadily, just a moment of teaching for him and not something far more precious like it is to Gen. "There's the not-really-North-Star-anymore! Even though it's not at true north anymore, we're—"

"We're what?" Gen asks, turning to face Senku, suddenly quiet.

Suddenly staring at their hands.

Well, he'd had to have realized what he was doing eventually.

The one who removes his hand—quickly, to save Senku from further embarrassment, and himself from an explanation—is Gen. His face is neutral. "We're what?" he asks again, doing his part by pretending what Senku believes was a mishap hadn't happened. People do not like to linger on embarrassment.

Senku clears his throat and tucks his hands behind his back. "We're sailing by it, since it's so recognizable. We just adjust as we go."

 _That's my Senku-chan_ , Gen thinks, almost says it, but pulls back knowing this is a precarious moment that can't be upset by anything even slightly sentimental. Instead he nods, politely and attentively. "Makes sense. So where's our other constellation friend Perseus?"

"The Big Dipper isn't actually a constellation, but an asterism," Senku says, recovering himself. This he knows; it's science, logical, grounded. Nothing ambiguous, like what's on someone else's mind or, worse, heart. (The opposite to Gen. Is it any wonder Gen is drawn to him?) "That's really just semantics. Constellations are officially recognized by astronomers, asterisms aren't, but we see them all the same." He shrugs. "Astronomers aren't here to get mad about it, so whatever. Anyway, Perseus is there." He looks down.

Gen follows his line of sight. It ends at his hand, poised over the ship's railing.

"I can point it out for you," Senku mumbles, "if that's fine with you. Sorry about earlier."

He's asking permission to hold his hand. Apologizing for not doing so before.

Gen's hand curls tighter on the railing, but his voice is practiced nonchalance as he says, "That's fine."

Senku takes it, hesitantly, lighter than before, and it'd be too easy to laugh and tease him about it, but Gen cannot, will not ruin this with things he doesn't mean. He lets it happen, in silence; has his hand guided to where Perseus graces the night, his index finger charting its stars.

"This is Perseus," Senku says, quietly. "Its stars have weird names. Mostly Greek letters in sequential order followed by 'Perseid,' since they're in Perseus."

"What, you're not going to tell me those?" Gen replies, just as soft.

He throws a grin his way. "No way you don't know your Greek letters. 'Psi' for psychology?"

Gen vaguely knows the Greek alphabet, picked up along his life for its common scientific use. Still, he would hear Senku talk about it. About anything, even the books Gen had written himself. No one knows those better than him, who authored them, but if—for whatever reason—Senku talked about them, Gen would listen.

"So, that's that," Senku says, and lets Gen's hand go.

"Thank you, Senku-chan." He folds his hands inside his sleeves, and rubs his thumb over his fingers like it'll prevent Senku's fleeting warmth from leaving him. "Feel any more inspired?"

"Eh, not really."

"Oh..."

"But," he says, with a lopsided smile, "I really needed to get out of the lab for a bit. I don't have hydrogen ion concentration calculations buzzing in my head anymore. I think I can tackle my agar-making anew!"

"Then you _are_ inspired," Gen says, nudging him with his elbow. "You're welcome, by-the-by."

"Yeah, yeah; thanks, Gen," Senku says, but it's through a laugh, and it feels like they're sailing by at the speed of light.

A lull in the conversation, but one that is contemplative, soft around its edges.

"If the petrification had never happened, do you think we'd have met?" Gen asks, unguarded, but it's too late, and it won't do to show it had been a mistake, so he holds onto his meaningless little smile and his distant gaze to the moon.

Until Senku immediately replies, "No; what kind of dumb question was that?"

Gen's shoulders droop, his smile loosened to a deliberate sigh that could mean anything. It will be heard the way he intended. But it puffs out of him with another meaning, secret, likely destined to be so until its reason for existing (hopefully never) fades. "Senku-chan, how blunt of you!" he says, raising his shoulders back up, pulling himself to a performer's grin. "I was on TV often, you know. You could have been a guest on the same show as me. The mentalist and the super smart high school science prodigy!"

"Nah. I'd have turned an offer like that down."

One of Gen's hands flies to his chest, over his heart, in feigned (is it?) hurt. " _Blunt_!"

Senku puts on a smirk, but it's quirked to lessen his tone in something silent, something like an inside joke, something for the two of them. "Fame's never been for me. But what would I have done if I'd gone? Your party tricks and my science can't be matched up."

"My 'party tricks,'" Gen lilts, and he knows what he is going to say, where he is going, "got you a telescope." What he doesn't know is how Senku will reply. He wants to; it's why he'd brought it up. Disguised as a defense to his pride, insight into the sole gift, meager as it was, he has provided Senku.

The response isn't immediate—in words, at least, because the stars and the moon, brilliant with nothing to sully the skies, provide enough light for Gen to see the softening in the corners of Senku's eyes, the sheen of the heavens reflected upon them. "That wasn't your mentalist knowledge," Senku says, a moment later. "It was plain ol' science you remembered. Science still wins."

"Ah," he says, tilting his head to Senku, "but how do you think I got the village to help make it? Certainly not because of Einson or Edistein or what-have-you."

Senku huffs out resignation, but gently, acknowledging a dent in his logic. "Fair enough." And he doesn't even correct Gen's scientist switch-up, having recognized it for one of many things Gen will do exactly to instigate a desired response—annoyance, in this instance, if it had worked. But they have been together long enough that Senku accepts it is just one of Gen's quirks, part of having him around.

Has Senku figured out why Gen does _other_ things? The fear flits in-and-out of Gen's mind, but never on his expression. Obviously Senku hasn't. Gen would have noticed; it would have brought a change, however minute, to Senku's psyche. Particularly in this conversation.

He's the same as ever. That should be a good thing, and yet a part of Gen's chest, somewhere inside it, feels like it was never broken free of stone.

So Senku doesn't correct Gen. But neither does Gen correct himself: it had not been psychology that got a village to make a thing of the past and yet more modern than anything they could have imagined. It was Senku himself, magnetic as the wire curled around the copper rod he'd returned to existence. To give back to him as he'd given to them all wasn't even an easy choice, it was the obvious, the expected, the only thing that could be because everybody likes him.

 _Some of us somewhat differently than others_ , Gen thinks, drifting his eyes away from Senku and to the stars, and how much dimmer they are than the light he gives off.

To selfishly keep Senku out here by his side a while longer, he says, "Is Capricorn up there?"

Senku hums, eyes narrowed as he searches. "Yeah. It's always been kind of faint, but since the sky is so clear now, I can see it better." He glances at Gen. "Why are you curious about that one?"

"Why, it's you, Senku-chan! Your astrological sign! This journey is most definitely lucky if Perseus and Capricorn are watching over us simultaneously."

Senku's face falls to something like disgust.

Gen laughs, the sound carrying in the open sea, their ship the only thing to mar it. "It's just a joke! I'm not counting on the stars to see us through."

Not the stars above them, anyway.

"One last thing," Gen says, and sticks his tongue from the corner of his mouth as he blindly rummages through his sleeve pockets, shortly flourishing a sprig of lavender with a, "Ta-da!"

Senku's eyes widen. "Lavender? Where and when did you get it?"

Gen ignores that. "Once you're done science-ing for tonight, make yourself some tea out of it," he says, holding the sprig out for Senku. "It'll help you sleep!"

Senku looks between the lavender and Gen, Gen and the lavender. And smiles. "Thanks, Gen," he says, the quietest he's been yet, and takes the sprig just over Gen's fingers. No point of contact between them in the exchange. Better that way. Otherwise, Gen might not have been able to manage passivity on his face. "I think I'll continue my experiments tomorrow morning, though. You're right; I should rest."

Gen nods, pleased.

"So," Senku says, rubbing his neck, "uh, goodnight." Words aren't his specialty.

But that's why he has Gen. Whose mouth turns up, the barest bit, yet so much honesty in it. "Goodnight, Senku-chan."

Senku disappears below deck, the lavender firm in his hand. As the other meaning of lavender stays firm in Gen's mind. He'd been truthful, but not wholly. Lavender aids in sleep. And a gift of lavender symbolizes devotion.

Perhaps 'gift' is too strong a word for a fistful of a flower, but it's all Gen can presently give him. There'll be time yet for things more proper, things that will again let Gen see Senku so moved. But he has to take this a little at a time. Has to and will. The stars weren't mapped in a day.

**Author's Note:**

> -[agar is extracted from red seaweed.](http://www.fao.org/3/y4765e/y4765e06.htm#:~:text=3.1.,to%20remove%20the%20residual%20seaweed.) the genus _gracilaria_ would be the one senku needs, [species of which grow in jpn](https://marine-aquaculture.extension.org/seaweed-aquaculture-gracilaria/). it's used to make agar plates, which is a way of culturing bacteria (it can also be used to make agarose, which is used in making gels for [dna electrophoresis](https://www.bio-rad.com/featured/en/agarose-gel-electrophoresis.html), but the technology required for that is more advanced than what senku currently has. i think culturing bacteria should be a priority in the stone world for antibiotic production but that's partly my microbiology loving ass speaking). also u can eat agar; it's a common vegetarian-friendly gelatin substitute
> 
> -perseus was a greek hero, like the manga mentions, but it's also a [constellation](https://www.solarsystemquick.com/universe/perseus-constellation#:~:text=Perseus%20is%20easily%20visible%20in,mid%20spring%20to%20early%20summer.)
> 
> -[the night sky would change over time](https://spaceplace.nasa.gov/review/dr-marc-space/constellations.html). 3000 yrs shouldn't have a drastic effect, i.e. the sky would be fairly recognizable, [esp for the big dipper, whose stars orbits' are gravitationally bound to e/o so they'd stay in place](https://earthsky.org/favorite-star-patterns/big-and-little-dippers-highlight-northern-sky). but w/ the earth's axis tilted i think it'd be a little fuckier than expected
> 
> -i didn't make up [asterisms](https://astronomy.swin.edu.au/cosmos/A/Asterism)
> 
> -the greek letter [psi (Ψ)](https://en.wikipedia.org/wiki/Psi_\(Greek\)) is a symbol for psychology. among other sciencey things. we love to reuse these bitches
> 
> -in hanakotoba, lavender can mean ['devotion.'](https://hananokotoba.com/the-language-of-flowers/) it really only grows in [hokkaido](https://alljapantours.com/japan/travel/where-to-go/japanese-flowers-lavender-farms/) which isn't where the story is set. as to how gen got it... he's a Magician
> 
> -title from [this](https://planetary-science.org/astronomy/the-celestial-globe/). there's a metaphor in there somewhere for these 2


End file.
